As the fighting continues in Sierra Leone, BBC News Online looks at the strengths and weaknesses of the different sides in the conflict - the rebels, the government troops with their allies, and - caught in between - the UN forces:

RUF rebels

The rebels have shown they can take on detachments of United Nations peacekeepers and win.

Renowned for wanton barbarity, and staffed partly by child soldiers, the rebels are presenting a strong challenge to the poorly-trained national army and the lightly-armed UN peacekeeping force.

Thanks to its wealth from the sale of diamonds, the RUF is believed to be well supplied with a variety of weapons.

RUF fighter: terror tactics

In March 1999 Human Rights Watch alleged that 68 tonnes of weapons flown from Ukraine to Burkina Faso were diverted to the RUF.

The shipment apparently included Kalashnikov assault rifles, machine guns, rocket-propelled grenades, surface-to-air missiles and anti-tank weapons, and may have been only one of five such deliveries in 1998 and 1999.

It has been estimated that the RUF has 5,000 to 10,000 combat troops, though experts say the figure would be higher if arms-carrying youngsters were included in the count.

As part of its efforts to disarm them the UN had taken 4,000 weapons from the rebels by the end of April.

UN forces

The UN has complained that its peacekeeping operations are conducted on a shoestring, leading to problems with equipment failure, while others say that the peacekeepers simply haven't got the powerful weapons they need.

Defence analysts say a disciplined, well-armed force - such as the Western units sent to Bosnia and Kosovo - would have little difficulty in deterring Foday Sankoh's Revolutionary United Front (RUF).

The BBC's defence correspondent, Jonathan Marcus, says that one of the problems of the existing UN force is that its soldiers - from Nigeria, Kenya, Ghana, India, Guinea, Jordan and Zambia - have little training for peacekeeping operations, and have no previous experience of working together.

The mandate of the UN force is to "stabilise" the situation, so it has the powers to shoot back and use force, but in a battle at Masiaka, 220 Nigerian and Guinean soldiers were outgunned.

Armed with only light weapons, they were forced to withdraw when their ammunition ran out.

The UN force, meanwhile, currently numbers 8,700, well below its full strength of 11,000. Secretary-General Kofi Annan has called for urgent reinforcements.

Pro-government forces

Aside from the UN, the forces facing the RUF are the Sierra Leonean Army (SLA) - which is currently allied with the Armed Forces Revolutionary Council (AFRC) headed by former military ruler Johnny Paul Koroma - and civil defence forces including the Kamajors, militiamen originally from a tribe of hunters.

UK soldier: a well-trained Western force would restore order

The International Institute for Strategic Studies estimates the strength of the national armed forces at 3,000 poorly-armed men.

The British government has been training them, but a BBC regional analyst, Tom Porteous, says the army's tendency to disintegrate in times of trouble means that it is of little use.

Soldiers have in the past defected both to the RUF and to Koroma's AFRC. Both of these groups took part in a devastating invasion of Freetown in January 1999, and both joined the government after July's peace deal. The AFRC remains loyal.

The Kamajors, led by Deputy Defence Minister Sam Hinga Norman, fought effectively against the Koroma junta at the beginning of 1998, in an attack co-ordinated with the Nigerian-led West African intervention force, Ecomog.

As Ecomog stormed Freetown, the Kamajors fought their way up through the country from their stronghold in the south-east.

The recent history of Sierra Leone shows that mercenaries ... may be the best answer

Author, William Shawcross

Because of the successful experience of the Nigerian-led Ecomog forces the US is discussing the possibility of financing the return of Nigerian battalions to the country to take on the RUF again.

Mercenary option

Other options could include hiring private military firms.

Tim Spicer, the director of Sandline - a British company at the centre of a scandal supplying arms to ousted president Ahmad Tejan Kabbah two years ago - told London's Guardian newspaper that privately run forces could put the RUF "right back in its box".

The author and journalist, William Shawcross, argued in the same newspaper that developed countries should hire merceneries to enforce peace in Sierra Leone, if they were reluctant to send their own soldiers.

He said a group called Executive Ooutcomes had succeeded in protecting civilians in some areas from rebel atrocities until President Kabbah was persuaded to make peace with the rebels, and, in the process, to dispense with the company's services.